Date of Graduation

Document Type

Degree Name

Degree Level

Department

Advisor

Committee Member

Second Committee Member

Matt McIntosh

Third Committee Member

Roger Koppe

Fourth Committee Member

Suresh Thallapuranam

Keywords

Clostridium Histolyicum, Collagenase, Hathewaya Histolytica, SAXS

Abstract

Hathewaya histolytica, previously renamed as Clostridium histolyticum, secretes at least two collagenases, ColH and ColG, that allow for degradation of extracellular matrices of animal tissue. Hathewaya histolytica virulence factors are proposed to undergo domain rearrangement upon secretion from the bacteria to the host. In order to accomplish this, collagenases seek the least ordered regions in collagen to efficiently disassemble the fibril. Two types of domains, Polycystic Kidney Disease-like (PKD) and Collagen Binding Domain (CBD), direct the collagenases ability to disassemble the fibril. Calcium dependent structural change have been reported to increase in thermal stability and in tighter collagen binding for CBD. Different surface properties and indications of varied dynamics suggest unique roles for the PKD-like domains in ColG and in ColH. These domains are useful in anchoring fused growth factors to lesions. Most recent results show that use of multi-domain targeting segments result in more efficacious preclinical outcomes in various animal models. Single domain targeting segments have been biophysically characterized; however, multi-domain targeting segments have not been biophysically characterized. In this study, Small Angle X-Ray Scattering (SAXS) methods were used to monitor calcium dependent structural change of multi-domain segments, i.e. PKD1-PKD2-CBD and PKD-CBD1-CBD2 (Ruth and Sakon 2017). All SAXS data were collected at 10°C through the Advanced Light Source at Berkley National Lab (Otwinowski and Minor 1997) (Classen, Hura et al. 2013). The average of 33 beam exposures were collected and processed through primusqt (Konarev, Petoukhov et al. 2006). Genes for type II secretion system are recently reported in the genus. The bacteria apparently evolved to take advantage of calcium concentration differential from inside the bacteria and the extracellular matrix to efficiently secrete virulence factors